s-Triazine (1,3,5-triazine) derivatives have been researched in the fields of synthetic resins, synthetic fibers and agricultural chemicals and a number of such compounds have been synthesized. In the field of pharmaceuticals, researches have been made with respect to antitumor, anti-inflammatory, analgesic and antispasmodic activities. Especially, hexamethylmelamine (HMM) is well-known, which has been developed as analogue of antitumor agent triethylenemelamine (TEM) [B. L. Johnson et al. Cancer, 42:2157-2161 (1978)].
TEM is known as an alkylating agent and is an s-triazine derivative having cytotoxic antitumor activity. HMM has been marketed in Europe under the indications for the treatment of ovarian and small cell lung cancers, and its action on solid cancers has been attractive.
As to its antitumor spectrum and antitumor activity against solid cancers, however, there has been still room for improvement.